refactor: remove terminal agent concept entirely

Remove the "agent can be a terminal" branching from the entire codebase.
An agent is now always a session-backed chat agent. Standalone terminal
infrastructure (terminal component, ANSI handling, terminal-stream-protocol)
is preserved.

Server: delete ManagedTerminalAgent, AgentKind, TerminalExitDetails,
launchTerminalAgent, registerTerminalAgent, handleTerminalAgentExited,
supportsTerminalMode capability, buildTerminalCreate/ResumeCommand from
all providers, terminal agent persistence/projections.

App: delete terminal-agent-panel.tsx, terminal-agent-reopen-store.ts,
terminal/terminalExit fields on agent state, "Terminal Agents" launcher
section, terminal-agent workspace setup flow, terminal badge in agent list.

CLI: remove terminal column from ls, terminal-agent error from send.

60 files changed, -3592 lines

packages/app/src/hooks/use-agent-screen-state-machine.test.ts

@@ -17,7 +17,6 @@ function createAgent(id: string): Agent {
     serverId: "server-1",
     id,
     provider: "claude",
-    terminal: false,
     status: "running",
     createdAt: now,
     updatedAt: now,
@@ -30,7 +29,6 @@ function createAgent(id: string): Agent {
       supportsMcpServers: true,
       supportsReasoningStream: true,
       supportsToolInvocations: true,
-      supportsTerminalMode: false,
     },
     currentModeId: null,
     availableModes: [],

packages/app/src/hooks/use-agent-screen-state-machine.ts

@@ -6,13 +6,6 @@ export interface AgentScreenAgent {
   status: "initializing" | "idle" | "running" | "error" | "closed";
   cwd: string;
   lastError?: string | null;
-  terminalExit?: {
-    command: string;
-    message: string;
-    exitCode: number | null;
-    signal: number | null;
-    outputLines: string[];
-  } | null;
   projectPlacement?: {
     checkout?: {
       cwd?: string;

packages/app/src/hooks/use-aggregated-agents.ts

@@ -65,7 +65,6 @@ export function useAggregatedAgents(options?: {
           serverId,
           serverLabel,
           title: agent.title ?? null,
-          terminal: agent.terminal,
           status: agent.status,
           lastActivityAt: agent.lastActivityAt,
           cwd: agent.cwd,

packages/app/src/hooks/use-all-agents-list.test.ts

@@ -8,7 +8,6 @@ function makeAgent(input?: Partial<Agent>): Agent {
     serverId: "server-1",
     id: input?.id ?? "agent-1",
     provider: input?.provider ?? "codex",
-    terminal: input?.terminal ?? false,
     status: input?.status ?? "idle",
     createdAt: input?.createdAt ?? timestamp,
     updatedAt: input?.updatedAt ?? timestamp,
@@ -21,7 +20,6 @@ function makeAgent(input?: Partial<Agent>): Agent {
       supportsMcpServers: true,
       supportsReasoningStream: true,
       supportsToolInvocations: true,
-      supportsTerminalMode: false,
     },
     currentModeId: input?.currentModeId ?? null,
     availableModes: input?.availableModes ?? [],

packages/app/src/hooks/use-all-agents-list.ts

@@ -19,7 +19,6 @@ function toAggregatedAgent(params: {
     serverId: params.serverId,
     serverLabel: params.serverLabel,
     title: source.title ?? null,
-    terminal: source.terminal,
     status: source.status,
     lastActivityAt: source.lastActivityAt,
     cwd: source.cwd,

packages/app/src/hooks/use-archive-agent.test.ts

@@ -10,7 +10,6 @@ function makeAgent(overrides: Partial<Agent> = {}): Agent {
     serverId: "server-a",
     id: "agent-1",
     provider: "codex",
-    terminal: false,
     status: "running",
     createdAt: new Date("2026-04-01T03:00:00.000Z"),
     updatedAt: new Date("2026-04-01T03:00:00.000Z"),
@@ -23,7 +22,6 @@ function makeAgent(overrides: Partial<Agent> = {}): Agent {
       supportsMcpServers: true,
       supportsReasoningStream: true,
       supportsToolInvocations: true,
-      supportsTerminalMode: false,
     },
     currentModeId: null,
     availableModes: [],